My thunderbird account stopped receiving emails yesterday and is giving the message: "Thunderbird The certificate for pop3.exemail.com.au is not valid for that server. Someone could be trying to impersonate the server and you should not continue." Mails are still going to the Webmail account and my husband has an exemail account with the same settings that is working correctly. Exetel is in the process of selling its email service to a third party but this isn't final until September 8, will moving to the new provider fix this issue or is there something else I should be doing?